Mono Reissues and the Conical Stylus

'Maybe I should plug myself into a phono preamp. Any body try that?'
Sounds as if your already convinced but if you wish to, then go ahead.

My main point is: The difference I heard was as clearly audible as any I ever heard. Between a very good stereo and a "real mono" cartridge. It’s the kind of difference every non-audiophile hears, because it’s the difference between kind of fake and real life, it’s about musicality and direct connection to the musicians. I agree with you mijostyn that there is too much talk about micro-differences that are only relevant for audiophiles, which are not really relevant for the musical experience.
The rest of my post might be over the top of (your? others?) head, and / or you don’t like the difference to exist? I could understand that. I did so for quite a long time.
Regarding the conical stylus: The stereo cartridge had a very good line contact stylus, the Miyajima a 1um conical. The line contact to our ears didn’t swamp the electromechanical advantage of the "real mono" cartridge. Although it most probably would improve the latter, as Dave observed.
The review (Hifi News) of the 1um vs. the 0.7um version of the Miyajima hinted at even better sound with the bigger radius on "original" mono recordings. But the 0.7um is probably the safer bet, because it wan't harm any of the newer microgroove cut mono LPs (or mono reissues). I decided for the 1um because of the big stock of old monos in my family.

For as many years as I've been playing LPs I should know this.  But this thread helped me realize that I don't.

Early stereo LPs often contained warnings against playing with a mono cartridge.  Was that due to the larger conical mono stylus tip compared to elliptical stereo tip which might cause damage to the groove?

Or was it an issue with vertical motion of the stylus/cantilever?  I've read that true mono cartridges do not pick up vertical groove information.  I assume that is because of the coil configuration rather than the cantilever not being able to move vertically.  If it is the latter is that the reason it can cause groove damage?

The warning against playing a stereo record with a mono cartridge stems from the fact that the early mono cartridges didn't have or need any vertical compliance.  The lack of vertical movement effectively chews up any vertical modulation found in the 45º cut stereo groove. Some current day manufacture cartridges like the Miyajima's adhere to this while others have coils in the lateral plane with compliance in both the lateral and vertical plane.  The Denon 102 was designed as a mono cartridge with vertical compliance so radio stations could use the same cartridge to play both mono and stereo cuts.

dave

Thanks dave.  I suspected that so appreciate the confirmation.